Sleeping Time, if you are new, is a web app that lets you determine the sleeping pattern of any Twitter user as long as they have a public profile on Twitter (see sample report).

Sleeping Time launched in 2010 and since then, the app has been used to generate the sleeping schedules of more than 500,000 Twitter users. The response was unexpected and it even made it to the front page of a newspaper.

The app reads the time-stamp of the last 1,000 tweets of a Twitter user and then estimates their sleep cycle based on hours when he or she is least active on Twitter. To get started, sign-in with your Twitter account (it will never post anything to Twitter on your behalf) and enter the user name of any Twitter user to see their sleeping pattern.

Here’s what’s new /changed in Sleeping Time v2.0:

The algorithm has been tweaked and the app should thus provide even more accurate sleeping estimates.

Internally, the app is now powered by WordPress (PHP) while the previous version was on Google App Engine (Python).

The app is better equipped to handle the limitations of Twitter API that go into effect next month.

Google Image Charts are likely to discontinued in April 2012 and hence we have switched to the JavaScript based Google Charts. You can always use the web screenshots tool to save your report as an image.

Amit Agarwal is a web geek and founder of Digital Inspiration, a popular tech & how-to website. He has been blogging for over a decade and has also contributed to the Wall Street Journal, Lifehacker and The Financial Express. Sign-up for the email newsletter for your daily dose of tips & tutorials.